The purpose of this experiment was to determine the effect of temperature
on the elasticity of a rubber band.

I became interested in this experiment when I was doing a report on
Charles Goodyear in school. He invented vulcanized rubber. I have also
noticed that rubber bands that had been in cold temperatures would break
easily and I wanted to know what would happen if they were in warm temperature.

The information gained from this experiment may help companies or people
that are going to store rubber bands in warm or cold temperatures. It could
also help companies or stores that sell things that are made of rubber
such as tires.

HYPOTHESIS

My hypothesis was that the rubber bands stored in 0 degrees celsius
temperature would not be as elastic as the ones stored in 20 degrees celsius
or 75 degrees celsius temperature.

I based my hypothesis on my research, observations, and an Internet
site I visited. It stated that rubber bands stored in cold temperatures
would not be as elastic as ones stored in room temperature or warm temperature.

EXPERIMENT DESIGN

The constants in this study were:
- The brand of rubber
bands.
- The scale I will
use.
- The size of the
rubber bands.
- The amount of time
the rubber bands are stored in the temperatures before testing.
- The oven.
- The freezer.
- The color of the
rubber bands.

The manipulated variable was the temperature the rubber bands were stored
in before the tests.

The responding variable was how much force the rubber bands could take
before they broke.

To measure the responding variable I used a spring scale and I measured
the elasticity in kilograms.

MATERIALS

QUANTITY

ITEM DESCRIPTION

75

Rubber Bands

1

Spring Scale

1

Oven

1

Freezer

1

Glove

PROCEDURES

1. Gather all materials.
2. Separate 3 groups with 25 rubber bands in each group.
3. Put 1 group of 25 rubber bands in a freezer at 0 degrees
celsius temperature.
4. Store it there for 3 hours.
5. Take all of the rubber bands in that group out.
6. Take 1 of the rubber bands and put it on the spring
scale and pull it down.
7. Right before it breaks read what it says on the scale.
8. Record your data.
9. Do this with every rubber band.
10. Put another group of 25 rubber bands in room temperature set at
20 degrees celsius temperature.
11. Repeat steps 4 through 9.
12. Put another group of 25 rubber bands in an oven at 75 degrees celsius
temperature.
13. Repeat steps 4 through 9.

RESULTS

The original purpose of this experiment was to determine if temperature
affected the elasticity of a rubber band.

The results of the experiment were that the rubber bands stored at the
coldest temperature were the most elastic. The rubber bands stored at room
temperature were the second most elastic. And the rubber bands stored at
the warmest temperature were the least elastic.

My hypothesis was that rubber bands stored in 0 degrees celsius temperature
will not be as elastic as the ones stored in 20 degrees celsius and in
75 degrees celsius temperature. The results indicate that this hypothesis
should be rejected. The rubber bands in the warmest temperatures were not
as elastic as the other ones. The most elastic ones were in the coldest
temperature.

These findings should be useful to companies, stores, or people that
are going to store rubber bands.

Because of this experiment, I wonder if all things made of rubber are
effected by temperature? If this were true then companies that store tires
and other important things would be able to use this information.

If I were to conduct this experiment again I would test the rubber bands
in the temperature instead of storing them in it before the test. That
would be a more useful experiment.

RESEARCH
REPORT

Introduction

This research will include information about rubber bands, such as what
are they are made of and how are they made. It will have information about
rubber, such as how rubber is used and how it used to be made. It will
have information about temperature and heat, such as how it is measured
and how to convert units of temperature into other units of temperature.
It will also include information about elasticity.

Rubber Bands

A rubber band is made of natural rubber, calcium carbonate, carbon
black, clay, sulfur, stearic acid, zinc oxide, wax, and oil.
Rubber bands are made by mixing all of the ingredients together.
Then it is put into a machine called a "extruder" to make it into a tube.
Then it is put into a pressurized steam tank. This gives the rubber band
its round shape and great strength. This process is called "vulcanization."
Then the long round tube is cut into tiny rings.
Rubber bands are measured in three dimensions. The are measured
by length, width, and thickness. The distance from end to end when laid
flat is the length. The width of the band is measures how wide it is, perpendicular
to the length. The thickness measures the wall of the rubber band.

Rubber

In the United States about three-fifths of the rubber we have
is used for automobiles, airplanes, busses, tractors, and construction
machinery. Rubber is used for a lot of household products too. Manufacturers
use it make things waterproof. It can be used as an insulator if it was
made into foam. It is also used to make rubber cement. Rubber is grown
on plantations, usually in Thailand, Indonesia, and Malaysia. The world’s
rubber production is about nine million metric tons.
Rubber, long ago, did not work very well. That was before people
knew how to vulcanize it. It became sticky in hot weather, and stiff and
brittle in cold weather. But in 1839 Charles Goodyear invented vulcanized
rubber. Tires that used the early rubber would last 300 to 500 miles but
now tires last a lot longer usually 30,000 to 50,000 miles or more.

Temperature

Temperature is how hot or cold something is as measured on a particular
scale. The two most common ways of measuring temperature are Celsius and
Fahrenheit. Another way to measure temperature is Kelvin. Instruments that
measure temperature are called thermometers. The formula for converting
Fahrenheit to Celsius is °C=(°F-32)/1.8. The formula for converting
Celsius to Kelvin is °K=°C+273.

Heat

People use heat in many ways. People use it in their homes to
make them more comfortable. It also allows people to have hot water.
There are a lot of sources of heat. The most common ones are
the sun, the earth, chemical reactions, electricity, and friction.
Heat is the most important form of energy. Heat and energy cannot
be seen, but the work they do can. Everything is made up of atoms or molecules,
which are always moving. The motion gives the object internal energy. The
level of an object’s internal energy depends n how rapidly it’s atoms or
molecules move. If they move slowly, the object has a low level of internal
energy. If they move violently, it has a high level of internal energy.
If an object has a high internal energy it is hot, but if it has a low
internal energy it is cold.

Elasticity

Elasticity is the ability to return to an original shape after
being deformed by a force. All solids have elasticity. If the stress applied
to a solid exceeds its elastic limit it will not return to its original
shape. Stress is related to strain. Strain measures how much a given dimension
of a solid changes under stress. The greater the stress, the greater the
strain. The ratio of stress to strain is called the elastic modulus. Object
with a high elastic modulus, such as steel, has a stronger resistance to
stress than an object with a low elastic modulus, such as rubber. The equation
of the elasticity of a rubber band is (delta L)= (FL)/(EA) where
(delta L)= length change, F= force, L= length, E= elastic modulus, and
A= cross-sectional area.

Summary

Rubber is a very useful substance, made better by vulcanization.
Elasticity is what makes rubber a perfect material for making rubber bands,
tires, and bumpers.